WO2016117972A1

WO2016117972A1 - Method and device for transmitting data for plurality of stations through plurality of bands in wireless lan system

Info

Publication number: WO2016117972A1
Application number: PCT/KR2016/000747
Authority: WO
Inventors: 최진수; 조한규; 이욱봉; 류기선
Original assignee: 엘지전자 주식회사
Priority date: 2015-01-22
Filing date: 2016-01-22
Publication date: 2016-07-28
Also published as: US20180006781A1; US10461901B2

Abstract

Proposed are a method and a device for transmitting a signal including a data field in a wireless LAN. For example, an access point (AP) allocates, to a second station, a second frequency band adjacent to a first frequency band, wherein the second frequency band can include a plurality of resource units. In addition, a signal including the data field can be transmitted to the second station through the allocated second frequency band. Furthermore, when the first frequency band is allocated to the first station, the AP can allocate, to the second station, as a null resource unit, a resource unit adjacent to the first frequency band among the plurality of resource units.

Description

Method and apparatus for transmitting data for multiple stations over multiple bands in wireless LAN system

TECHNICAL FIELD This disclosure relates to wireless communications, and more particularly, to a method and apparatus for transmitting data for multiple stations over multiple bands in a wireless LAN system.

Discussion is underway for the next generation wireless local area network (WLAN). In next-generation WLANs, 1) enhancements to the Institute of Electronics and Electronics Engineers (IEEE) 802.11 physical physical access (PHY) and medium access control (MAC) layers in the 2.4 GHz and 5 GHz bands, and 2) spectral efficiency and area throughput. aim to improve performance in real indoor and outdoor environments, such as environments with interference sources, dense heterogeneous network environments, and high user loads. .

The environment mainly considered in the next-generation WLAN is a dense environment having many access points (APs) and a station (STA), and improvements in spectral efficiency and area throughput are discussed in such a dense environment. In addition, in the next generation WLAN, there is an interest in improving practical performance not only in an indoor environment but also in an outdoor environment, which is not much considered in a conventional WLAN.

Specifically, in the next-generation WLAN, there is a great interest in scenarios such as wireless office, smart home, stadium, hotspot, building / apartment, and AP based on the scenario. And STA are discussing about improving system performance in a dense environment with many STAs.

In addition, in the next-generation WLAN, there will be more discussion about improving system performance in outdoor overlapping basic service set (OBSS) environment, improving outdoor environment performance, and cellular offloading, rather than improving single link performance in one basic service set (BSS). It is expected. The directionality of these next-generation WLANs means that next-generation WLANs will increasingly have a technology range similar to that of mobile communications. Considering the recent situation in which mobile communication and WLAN technology are discussed together in the small cell and direct-to-direct (D2D) communication area, the technical and business convergence of next-generation WLAN and mobile communication is expected to become more active.

An object of the present specification is to propose an example of transmitting data signals for multiple stations over multiple bands in a wireless LAN system.

More specifically, in the conventional wireless LAN system, when allocating resources or transmitting signals for a specific station on a discontinuous band, a problem occurs due to interference or the like. One example of the present specification can be used to solve this problem.

The present specification proposes a method for transmitting a signal including a data field in a wireless LAN and a station (AP or non-AP) implementing the same.

Specifically, the access point (AP) may allocate a second frequency band adjacent to the first frequency band to the second station, wherein the second frequency band may include a plurality of resource units.

In addition, a signal including the data field may be transmitted to the second station through the allocated second frequency band.

In addition, when the first frequency band is allocated to the first station, the AP allocates the second station as a null resource unit to a resource unit adjacent to the first frequency band among the plurality of resource units. can do.

In addition, the transmitting station allocates a second frequency band adjacent to the first frequency band as a transmission band to an access point (AP), wherein the second frequency band may include a plurality of resource units.

In addition, a signal including the data field may be transmitted to the AP through the allocated second frequency band.

In addition, when the first frequency band is used by another transmitting station, the transmitting station may use a resource unit adjacent to the first frequency band among the plurality of resource units as a null resource unit. .

One example herein is to efficiently transmit data signals for multiple stations over multiple bands.

1 is a conceptual diagram illustrating a structure of a wireless local area network (WLAN).

2 is a conceptual diagram illustrating a resource allocation method on an 80 MHz bandwidth according to the present embodiment.

3 is a conceptual diagram illustrating a resource allocation method on a 20 MHz bandwidth according to the present embodiment.

4 is a conceptual diagram illustrating a resource allocation method on a 20 MHz bandwidth according to the present embodiment.

5 is a conceptual diagram illustrating a resource allocation method on a 20 MHz bandwidth according to the present embodiment.

6 is a conceptual diagram illustrating assignment of the left guard tone according to the present embodiment.

7 is a conceptual diagram illustrating resource allocation on a 20 MHz bandwidth according to the present embodiment.

8 is a conceptual diagram illustrating resource allocation on a 20 MHz bandwidth according to the present embodiment.

9 is a conceptual diagram illustrating a resource allocation method on a 40 MHz bandwidth according to the present embodiment.

10 is a conceptual diagram illustrating a resource allocation method on a 40 MHz bandwidth according to the present embodiment.

11 is a conceptual diagram illustrating a resource allocation method on a 40 MHz bandwidth according to an embodiment.

12 is a conceptual diagram illustrating division of a 242 ton resource unit according to the present embodiment.

13 is a conceptual diagram illustrating a resource allocation method on a 20 MHz bandwidth according to the present embodiment.

14 is a conceptual diagram illustrating a resource allocation method on a 20 MHz bandwidth according to the present embodiment.

15 is a block diagram illustrating a method for allocating a plurality of frequency resources according to the present embodiment.

16 is a diagram for explaining an example of frequency resource allocation proposed in this embodiment.

17 is a diagram for explaining an example of frequency resource allocation proposed in this embodiment.

18 is a conceptual diagram illustrating a DL / UL PPDU format that can be used in the present embodiment.

19 is a block diagram illustrating a wireless device to which the present embodiment can be applied.

1 shows the structure of the infrastructure basic service set (BSS) of the Institute of Electrical and Electronic Engineers (IEEE) 802.11.

Referring to the top of FIG. 1, the WLAN system may include one or more infrastructure BSSs 100 and 105 (hereinafter, BSS). The BSSs 100 and 105 are a set of APs and STAs such as an access point 125 and a STA1 (station 100-1) capable of successfully synchronizing and communicating with each other, and do not indicate a specific area. The BSS 105 may include one or more joinable STAs 105-1 and 105-2 to one AP 130.

The BSS may include at least one STA, APs 125 and 130 for providing a distribution service, and a distribution system (DS) 110 for connecting a plurality of APs.

The distributed system 110 may connect several BSSs 100 and 105 to implement an extended service set (ESS) 140 which is an extended service set. The ESS 140 may be used as a term indicating one network in which one or several APs 125 and 230 are connected through the distributed system 110. APs included in one ESS 140 may have the same service set identification (SSID).

The portal 120 may serve as a bridge for connecting the WLAN network (IEEE 802.11) with another network (for example, 802.X).

In the BSS as shown in the upper part of FIG. 1, a network between the APs 125 and 130 and a network between the APs 125 and 130 and the STAs 100-1, 105-1 and 105-2 may be implemented. However, it may be possible to perform communication by setting up a network even between STAs without the APs 125 and 130. A network that performs communication by establishing a network even between STAs without APs 125 and 130 is defined as an ad-hoc network or an independent basic service set (BSS).

1 is a conceptual diagram illustrating an IBSS.

Referring to the bottom of FIG. 1, the IBSS is a BSS operating in an ad-hoc mode. Since IBSS does not contain an AP, there is no centralized management entity. That is, in the IBSS, the STAs 150-1, 150-2, 150-3, 155-4, and 155-5 are managed in a distributed manner. In the IBSS, all STAs 150-1, 150-2, 150-3, 155-4, and 155-5 may be mobile STAs, and access to a distributed system is not allowed, thus making a self-contained network. network).

A STA is any functional medium that includes medium access control (MAC) conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard and a physical layer interface to a wireless medium. May be used to mean both an AP and a non-AP STA (Non-AP Station).

The STA may include a mobile terminal, a wireless device, a wireless transmit / receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile subscriber unit ( It may also be called various names such as a mobile subscriber unit or simply a user.

Hereinafter, in the present embodiment, data (or frame) transmitted from the AP to the STA is called downlink data (or downlink frame), and data (or frame) transmitted from the STA to the AP is called uplink data (or uplink frame). Can be expressed in terms. In addition, the transmission from the AP to the STA may be expressed in terms of downlink transmission, and the transmission from the STA to the AP may be expressed in terms of uplink transmission.

In addition, each of the PHY protocol data units (PPDUs), frames, and data transmitted through downlink transmission may be expressed in terms of a downlink PPDU, a downlink frame, and downlink data. The PPDU may be a data unit including a PPDU header and a physical layer service data unit (PSDU) (or MAC protocol data unit (MPDU)). The PPDU header may include a PHY header and a PHY preamble, and the PSDU (or MPDU) may be a data unit including a frame (or an information unit of a MAC layer) or indicating a frame. The PHY header may be referred to as a physical layer convergence protocol (PLCP) header in another term, and the PHY preamble may be expressed as a PLCP preamble in another term.

In addition, each of the PPDUs, frames, and data transmitted through uplink transmission may be represented by the term uplink PPDU, uplink frame, and uplink data.

In the existing WLAN system, the entire bandwidth is used for downlink transmission to one STA and uplink transmission of one STA based on single-orthogonal frequency division multiplexing (SUDM) transmission. In addition, in the conventional WLAN system, the AP may perform DL (downlink) multi-user (MU) transmission based on MU MIMO (multiple input multiple output), and such transmission may be expressed by the term DL MU MIMO transmission. Can be.

In the WLAN system according to the present embodiment, an orthogonal frequency division multiple access (OFDMA) based transmission method may be supported for uplink transmission and downlink transmission. In more detail, in the WLAN system according to the present embodiment, the AP may perform DL MU transmission based on OFDMA, and such transmission may be expressed by the term DL MU OFDMA transmission. When DL MU OFDMA transmission is performed, the AP may transmit downlink data (or downlink frame, downlink PPDU) to each of the plurality of STAs through the plurality of frequency resources on the overlapped time resources. The plurality of frequency resources may be a plurality of subbands (or subchannels) or a plurality of resource units (RUs) (eg, a basic tone unit (BTU), a small tone unit (STU)). DL MU OFDMA transmission can be used with DL MU MIMO transmission. For example, DL MU MIMO transmission based on a plurality of space-time streams (or spatial streams) is performed on a specific subband (or subchannel) allocated for DL MU OFDMA transmission. Can be.

In addition, in the WLAN system according to the present embodiment, UL MU transmission (uplink multi-user transmission) may be supported that a plurality of STAs transmit data to an AP on the same time resource. Uplink transmission on the overlapped time resource by each of the plurality of STAs may be performed in the frequency domain or the spatial domain.

When uplink transmission by each of the plurality of STAs is performed in the frequency domain, different frequency resources may be allocated as uplink transmission resources for each of the plurality of STAs based on OFDMA. The different frequency resources may be different subbands (or subchannels) or different resource units (RUs) (eg, basic tone units (BTUs) and small tone units (STUs)). Each of the plurality of STAs may transmit uplink data to the AP through different allocated frequency resources. The transmission method through these different frequency resources may be represented by the term UL MU OFDMA transmission method.

When uplink transmission by each of the plurality of STAs is performed in the spatial domain, different space-time streams (or spatial streams) are allocated to each of the plurality of STAs, and each of the plurality of STAs transmits uplink data through different space-time streams. Can transmit to the AP. The transmission method through these different spatial streams may be represented by the term UL MU MIMO transmission method.

The UL MU OFDMA transmission and the UL MU MIMO transmission may be performed together. For example, UL MU MIMO transmission based on a plurality of space-time streams (or spatial streams) may be performed on a specific subband (or subchannel) allocated for UL MU OFDMA transmission.

In a conventional WLAN system that did not support MU OFDMA transmission, a multi-channel allocation method was used to allocate a wider bandwidth (for example, a bandwidth exceeding 20 MHz) to one UE. The multi-channel may include a plurality of 20 MHz channels when one channel unit is 20 MHz. In the multi-channel allocation method, a primary channel rule is used to allocate a wide bandwidth to the terminal. If the primary channel rule is used, there is a constraint for allocating a wide bandwidth to the terminal. Specifically, according to the primary channel rule, when a secondary channel adjacent to the primary channel is used in an overlapped BSS (OBSS) and 'busy', the STA may use the remaining channels except the primary channel. Can not. Therefore, the STA can transmit the frame only through the primary channel, thereby being limited to the transmission of the frame through the multi-channel. That is, the primary channel rule used for multi-channel allocation in the existing WLAN system may be a big limitation in obtaining high throughput by operating a wide bandwidth in the current WLAN environment where there are not many OBSS.

In order to solve this problem, the present invention discloses a WLAN system supporting an orthogonal frequency division multiple access (OFDMA) technique. When OFDMA technology is used, a plurality of terminals may be used simultaneously instead of one terminal without using a primary channel rule. Therefore, wide bandwidth operation is possible, and the efficiency of the operation of radio resources can be improved.

A time-frequency structure assumed in the WLAN system according to the present embodiment may be as follows.

The fast fourier transform (FFT) size / inverse fast fourier transform (IFFT) size may be defined as N times (N is a natural number, for example, N = 4) of the FFT / IFFT size used in a conventional WLAN system. . For example, 256 FFT / IFFT is applied for a bandwidth of 20 MHz, 512 FFT / IFFT is applied for a bandwidth of 40 MHz, 1024 FFT / IFFT is applied for a bandwidth of 80 MHz, and 2048 FFT for a bandwidth of 160 MHz continuous or discontinuous 160 MHz. / IFFT can be applied.

The subcarrier spacing may be 1 / N times the size of the subcarrier space used in the conventional WLAN system (N is a natural number, for example, 78.125 kHz when N = 4).

The IDFT / DFT length (or effective symbol length) based on inverse discrete fourier transform (IDFT) / discrete fourier transform (DFT) (or FFT / IFFT) may be N times the IDFT / DFT length in the existing WLAN system. . For example, in an existing WLAN system, if the IDFT / DFT length is 3.2 μs and N = 4, the IDFT / DFT length may be 3.2 μs * 4 (= 12.8 μs) in the WLAN system according to the present embodiment. have.

The length of an OFDM symbol may be a value obtained by adding a length of a guard interval (GI) to an IDFT / DFT length. The length of the GI can be various values such as 0.4 μs, 0.8 μs, 1.6 μs, 2.4 μs, 3.2 μs.

When the OFDMA-based method and apparatus according to the present embodiment are used, resource allocation units defined with different sizes may be used. The resource allocation unit may be represented by various names such as a unit, a resource unit, a resource unit, a frequency unit, and the like, and the size of each unit may be expressed in a tone unit corresponding to a subcarrier. The resource unit may be set in various ways. For example, it can be defined in various sizes such as 26, 52, 56 tons.

The resource unit includes a left guard tone, a right guard tone, and a center of the entire bandwidth for interference mitigation located at both ends of the overall bandwidth over the entire bandwidth (or available bandwidth). It may be allocated considering the direct current (DC) tone located at. The resource unit is leftover that can be used for user allocation separation (or resource allocation per STA), common pilot, automatic gain control, phase tracking, etc. ) Tones (or remaining tones) may be allocated.

The allocation method (allocation number, allocation position, etc.) of resource units on the entire bandwidth may be set in consideration of resource utilization efficiency and scalability (or scalability) according to the overall bandwidth. The allocation method of the resource unit may be signaled based on a predefined or various methods (eg, signaling based on a signal field included in the PPDU header of the PPDU).

In addition, according to the present embodiment, a virtual allocation resource unit including a tone corresponding to a combination between at least a plurality of resource units is defined, and resource allocation based on the virtual allocation resource unit may be performed. have. Resource allocation based on virtual allocation resource units may be referred to as virtualization in other words.

The virtual allocation resource unit may be a resource unit for recycling the interleaver size and OFDM numerology (or tone neuralology) of the existing WLAN system.

Specifically, when 242 tones are allocated to one STA, the existing pilot allocation and the existing interleaver size may be utilized. In more detail, a pilot tone may be allocated to 8 tons of the 242 tones and a data tone may be allocated to the remaining 234 tons. Interleaving based on a 234 interleaver may be performed on 234 tones of data tones.

In this case, the data interleaving procedure and the pilot tone insertion procedure may be performed in the same manner as the STA to which the existing 242 tones are allocated. That is, even if the 242-tone structure is not physically supported, one virtual 242-tone resource unit may be allocated to the STA. In this case, the interleaving procedure using the existing 234 interleaver and the insertion procedure of the existing pilot tones (8 pilot tones) may be used. The resource unit of 242 tons may be expressed in terms of a virtual allocation resource unit. The virtual allocation resource unit may be a multiple of 242 tons or 242 tons (eg, 484, 968, etc.). Alternatively, the size of the virtual allocation resource unit may be determined based on other interleaver sizes (108, 52, 24, etc.) used in the existing WLAN system.

According to the present embodiment, tone numerology for each of the bandwidths of 20 MHz, 40 MHz, and 80 MHz may be as follows. The resource allocation method of each bandwidth below is one example. In addition, resource allocation on each bandwidth may be performed in various ways.

The specific values below may be changed.

For example, for a 20 MHz bandwidth, the left guard tone is defined as 6 tones, the direct current (DC) tone is 3 tones, the right guard tone is defined as 5 tones, Resource units and five 26 tons of resource units may be allocated on the bandwidth. Alternatively, nine 26 tons of resource units may be allocated as virtual allocation resource units.

For example, the allocation on the specific 20 MHz frequency band may be 56/26/26/13 / DC / 13/26/26/56 or 26/26/13/56 / DC / 56/13/26/26. . 56 indicates 56 tons of resource units, 26 indicates 26 tons of resource units, and 13 indicates 13 tons of resource units, which is divided into 26 tons.

For example, for a 40 MHz bandwidth, the left guard tone is defined as 6 tons, the DC tone is 9 tones, the right guard tone is defined as 5 tones, and the remaining 492 tones are divided into two and three on each of the two divided 492 tones. 56 tonnes of resource units and three 26 tonnes of resource units may be allocated. The allocation on the specific 40 MHz frequency band may be 56/56/26/26/26/56 / DC / 56/26/26/26/56/56.

For example, for the 80 MHz bandwidth, the left guard tone is defined as 11 tons, the DC tone is 3 tones, the right guard tone is defined as 10 tones, the remaining 1000 tones are divided into four, and four on each of the 250 tones divided into four. 56 tons of resource units and one 26 tons of resource units may be allocated. Nine 26 tons of resource units may be allocated to each of four 250 ton units corresponding to a 20 MHz or 40 MHz half. Specific allocation on the frequency band of 40 MHz is 56/56/56/56/56/26/26/56/56/56/56 / DC / 56/56/56/56/26/26/56/56/56/56 days Can be.

Hereinafter, in this embodiment, stations using 20 MHz bandwidth as front-end bandwidth, stations using 40 MHz bandwidth as front-end bandwidth, and stations using 80 MHz bandwidth as front-end bandwidth may coexist. Tone numerology is disclosed for reducing interference with each other in a wireless LAN system. Meanwhile, since the front-end bandwidth indicates the maximum available bandwidth, for example, a station using the 40 MHz bandwidth as the front-end bandwidth may use not only 40 Mhz but also 20 Mhz bandwidth.

Hereinafter, a resource allocation method (or tone plan) for coexistence between terminals supporting different sizes of front-ends based on 242 tons of virtual allocation resource units (or 242 tons resource units) is disclosed.

In FIG. 2, 11 tons of left-most guard tone (or left guard tone), 3 tons of DC tone and 10 tons of right-most guard tone at 80 MHz front-end bandwidth If (or right guard tone) is assumed, allocation of resource units on the remaining 1000 tonnes (1024 to 24 tonnes) is initiated.

1000 tonnes can be divided into four 250 tonnes (242 tonnes of data and 8 tonnes of leftover tones).

Referring to the left side of FIG. 2, 11 (left guard tone) / 242/8/8/242 / DC / 242/8/8/242/10 (right guard tone) may be allocated on a bandwidth of 80 MHz. Here, 242 indicates a 242 ton resource unit, and 8 indicates 8 leftover tones.

A plurality of eight leftover tones may be continuously allocated among the 242 tone resource units. Leftover tones located between 242 ton resource units may be used as guard tones. There are two 8-ton leftover tones (16-ton left-overtones) between the 242-ton resource unit adjacent to the DC tone and the 242-ton resource unit adjacent to the left guard tone, and the 242-ton resource unit adjacent to the DC tone and the right Two 8-ton leftover tones (16 tonnes total) may be located between 242-ton resource units adjacent to the guard tone.

Referring to the middle of FIG. 2, 11 (left guard tone) / 242/8/242/8 / DC / 8/242/8/242/10 (right guard tone) may be allocated on a bandwidth of 80 MHz. Eight leftover tones may be located between 242 ton resource units and adjacent to (or between 242 ton resource units and DC tones) a DC tone.

Referring to the right side of Fig. 2, 11 (left guard tone) / 242/8/4/242/4 / DC / 4/242/4/8/242/10 (right guard tone) are allocated over a bandwidth of 80 MHz. Can be. Four leftover tones are allocated to adjacent positions based on the DC tone, and four leftover tones and eight leftover tones may be located adjacent to the 242 tone resource unit adjacent to the left guard tone. In addition, four leftover tones and eight leftover tones may be located adjacent to the 242-ton resource unit adjacent to the right guard tone.

In FIG. 3, tone numerology (or resource allocation on 20 MHz bandwidth) for an STA having a 20 MHz front-end bandwidth in consideration of resource allocation on the 80 MHz bandwidth disclosed in the left side of FIG. 2 is disclosed.

Referring to FIG. 3, on the 80 MHz bandwidth, 11 tons of left guard tones, a first 242 tons of resource units (80 MHz), 8 tons of first leftover tones, 8 tons of second leftover tones, and 2 242 tons of Resource unit (80 MHz), DC tone, 3 242 ton resource unit (80 MHz), 8 ton third leftover tone, 8 ton 4 leftover tone, 4 242 ton resource unit (80 MHz), 10 The right guard tone of the tone can be assigned.

A unit of 6 tons of left guard tone, 242 ton resource unit (20 MHz), and 5 tons of right guard tone may be allocated on the 20 MHz bandwidth.

Hereinafter, for convenience of description, the DC tones are not considered in FIGS. 3 to 5, but n DC tones may be included in intermediate positions in the 242 ton resource unit. In this case, 6 tons of left guard tone, 242 tons of resource unit (20 MHz) + DC tones, and 5 tons of right guard tone may be allocated on a 20 MHz bandwidth.

For example, an allocation position of an 11 th tone left guard tone allocated on an 80 MHz bandwidth and an allocation position of an adjacent first 242 tone resource unit (80 MHz) and an allocation position of a 242 tone resource unit (20 MHz) allocated on a 20 MHz bandwidth are set to be the same. Can be. In order to set the same allocation position of the first 242 tone resource unit (80 MHz) on the frequency axis as the allocation position of the 242 tone resource unit (20 MHz) allocated on the 20 MHz bandwidth, the allocation start position of the left guard tone defined on the 20 MHz bandwidth is set. It may be a position shifted five tones in a direction in which the frequency decreases from the allocation start position of the left guard tone defined on the 80 MHz bandwidth.

That is, in order to set the allocation position of the first 242 tone resource unit (80 MHz) and the allocation position of the 242 tone resource unit (20 MHz) allocated on the 20 MHz bandwidth, the allocation start position of the 20 MHz bandwidth is set to the allocation start position of the 80 MHz bandwidth. As a reference, it may be shifted by 5 tons in the direction of decreasing frequency.

On the contrary, in order to set the allocation position of the first 242 tone resource unit (80 MHz) and the allocation position of the 242 tone resource unit (20 MHz) allocated on the 20 MHz bandwidth to be the same, the allocation start position of the 20 MHz bandwidth is fixed and the allocation of the 80 MHz bandwidth The starting position may be shifted 5 tons in the direction of increasing frequency.

Alternatively, the allocation position of the fourth 242 resource unit (80 MHz) adjacent to the right guard tone of 10 tones allocated on the 80 MHz bandwidth and the allocation position of the 242 ton resource unit (20 MHz) allocated on the 20 MHz bandwidth may be set to be the same. have. In this case, the allocation start position of the right guard tone defined on the 20 MHz bandwidth may be a position shifted five tones in a direction in which the frequency increases from the allocation start position of the right guard tone defined on the 80 MHz bandwidth.

That is, in order to set the allocation position of the fourth 242 tone resource unit (80 MHz) and the allocation position of the 242 tone resource unit (20 MHz) allocated on the 20 MHz bandwidth, the allocation start position of the 20 MHz bandwidth is determined as the allocation start position of the 80 MHz bandwidth. As a reference, it may be shifted by 5 tons in the direction of increasing frequency.

On the contrary, in order to set the allocation position of the fourth 242 tone resource unit (80 MHz) and the allocation position of the 242 tone resource unit (20 MHz) allocated on the 20 MHz bandwidth to be the same, the allocation start position of the 20 MHz bandwidth is fixed and the allocation of the 80 MHz bandwidth The starting position may be shifted 5 tons in the direction of decreasing frequency.

In order to set the same allocation position of the second 242 tone resource unit (80 MHz) and the allocation position of the 242 tone resource unit (20 MHz) allocated on the 20 MHz bandwidth, no separate shifting is required. Similarly, in order to set the same allocation position of the third 242 tone resource unit (80 MHz) and the allocation position of the 242 tone resource unit (20 MHz) allocated on the 20 MHz bandwidth, no shifting is necessary.

In FIG. 4, a tone numerology for a STA having a 20 MHz front-end bandwidth in consideration of resource allocation on the 80 MHz bandwidth disclosed in the middle of FIG. 2 is disclosed.

As shown in FIG. 3, the technical features described in FIG. 3 are similarly applied to FIG. 4, but the specific tone positions are different from those in FIG. 3, and thus, further description of FIG. 4 will be omitted.

In FIG. 5, a tone numerology for an STA having a 20 MHz front-end bandwidth in consideration of resource allocation on the 80 MHz bandwidth disclosed in the right side of FIG. 2 is disclosed.

As shown in FIG. 3, the technical features described in FIG. 3 are equally applied to FIG. 5, but only detailed positions of the tones differ from those in FIG. 3, and thus, further description of FIG. 5 will be omitted.

Referring to FIG. 6, the left guard tone of 8 tons is divided into 5 tons and 3 tons, and the left guard tones of 3 tons are extracted from each of the two 8 ton left guard tones and then combined to generate 6 tons of left guard tones. can do. The positions of these 6 ton left guard tones can be assigned to correspond to the positions of the left guard tones of 6 tones on the 20 MHz bandwidth, and the positions of the remaining 5 tones (8 to 3 tons) of the left guard tones are 5 on the 20 MHz bandwidth. It may be assigned to correspond to the position of the right guard tone of the tone.

2 to 5 do not define the DC tone on the 20 MHz bandwidth, it is preferable that the DC tone is defined within the 20 MHz bandwidth. That is, it is preferable that an additional constant number of tones are allocated to the DC tones on the 20 MHz bandwidth.

In FIG. 7, resource allocation on a 20 MHz bandwidth additionally considering a DC tone on a 20 MHz bandwidth is disclosed.

Referring to FIG. 7, on the 20 MHz bandwidth, n DC tones 700 may be included as well as a left guard tone / right guard tone / 242 ton resource unit (hereinafter, 242 ton resource unit (20 MHz)). In this case, the positions of n DC tones 700 in 242 ton resource units (hereinafter, referred to as 242 ton resource units (80 MHz)) allocated on the 80 MHz bandwidth allocated at positions corresponding to the 242 ton resource units allocated on the 20 MHz bandwidth. A tone corresponding to may be punctured, that is, the position of the DC tone 700 defined on the 20 MHz bandwidth and the puncturing tone 750 included in the 242 tone resource unit (80 MHz). The position may be set identically.

If the number of tones allocated to the DC tone 700 on the 20 MHz bandwidth is 3, three tones corresponding to the positions of the DC tones located in the center within the 242 tone resource unit (80 MHz) may be punctured. Alternatively, when the number of tones allocated to the DC tone 700 on the 20 MHz bandwidth is 5, five tones corresponding to the positions of the DC tones located in the center in the 242 tone resource unit (80 MHz) may be punctured.

If the number of DC tones 700 allocated on the 20 MHz bandwidth is not small, the number of tons punctured in the 242 tone resource unit (80 MHz) increases. An increase in the number of punctured tones can result in loss of radio resources in the 80 MHz bandwidth.

Hereinafter, the present embodiment discloses a method for reducing the loss of radio resources due to the increase in the number of tones to be punctured.

In FIG. 8, resource allocation on a 20 MHz bandwidth in which DC tones are additionally considered on a 20 MHz bandwidth is disclosed. In particular, a method is disclosed for reducing the loss of radio resources due to an increase in the number of tones processed.

Null tones 850 corresponding to the number of DC tones 800 may be inserted in the 242 tone resource unit (80 MHz) corresponding to the DC tones defined on the 20 MHz bandwidth. The null tone 850 means all empty subcarriers in which no signal such as data is carried.

In this case, a part of the guard tone allocated on the 80 MHz bandwidth may be used as the null tone 850 and included in the 242 tone resource unit (80 MHz).

The number and location of null tones included in the 242-tone resource unit (80 MHz) may be the same as the location and number of DC tones defined in the 20 MHz bandwidth.

Such a method can be applied to the resource allocation method on the 80 MHz bandwidth and the resource allocation method on the 20 MHz bandwidth described in FIGS.

In FIG. 9, a tone neuron for a STA having a 40 MHz front-end bandwidth in consideration of resource allocation on the 80 MHz bandwidth disclosed in the left side of FIG. 2 is disclosed.

Referring to FIG. 9, resource allocation for an STA having a 40 MHz front-end bandwidth includes a left guard tone, a first 242 tone resource unit (40 MHz), a first leftover tone (40 MHz), a DC tone, and a second leftover tone. (40 MHz), the second 242 tone resource unit (40 MHz), and the right guard tone.

For example, an 11 ton left guard tone allocated on an 80 MHz bandwidth and an allocation position of an adjacent first 242 tone resource unit (80 MHz) and an allocation position of a first 242 tone resource unit (40 MHz) allocated on a 40 MHz bandwidth are the same. It can be set to. Further, the allocation position of the second 242 tone resource unit (80 MHz) and the allocation position of the second 242 tone resource unit (40 MHz) allocated on the 40 MHz bandwidth may be set to be the same. Shifting of the allocation start point of the left guard tone may be performed to set the allocation position on the 40 MHz bandwidth as described above.

For the adjustment of the above position setting, the sum of the first left over tone, the DC tone, and the second left over tone can be set to 16 tons, and the remaining tones (512 tons-(484 tons + 16 tons) = 12 tones) May be set to the left guard tone and the right guard tone.

In FIG. 10, tone numerology is disclosed for an STA having a 40 MHz front-end bandwidth in consideration of resource allocation on the 80 MHz bandwidth disclosed in the middle of FIG. 2.

Referring to FIG. 10, resource allocation for an STA having a 40 MHz front-end bandwidth includes a left guard tone, a first 242 tone resource unit (40 MHz), a first leftover tone, a DC tone, a second leftover tone, and a second It may be performed based on a 242 ton resource unit (40 MHz), the right guard tone.

For the adjustment of the above position setting, the sum of the first leftover tone, the DC tone, and the second leftover tone can be set to 8 tones, and the remaining tones (512 tons (484 to +8 tons) = 20 tones) May be set to the left guard tone and the right guard tone.

Alternatively, the first leftover tone and the second leftover tone are not defined, and the DC tone may be set to 8 tones.

In FIG. 11, tone neuron is disclosed for an STA having a 40 MHz front-end bandwidth in consideration of resource allocation on the 80 MHz bandwidth disclosed in the right side of FIG. 2.

Referring to FIG. 11, resource allocation for an STA having a 40 MHz front-end bandwidth includes a left guard tone, a first 242 tone resource unit (40 MHz), a first leftover tone, a DC tone, a second leftover tone, and a second It may be performed based on a 242 ton resource unit (40 MHz), the right guard tone.

For example, an 11 ton left guard tone allocated on an 80 MHz bandwidth and an allocation position of an adjacent first 242 tone resource unit (80 MHz) and an allocation position of a first 242 tone resource unit (40 MHz) allocated on a 40 MHz bandwidth are the same. It can be set to. Further, the allocation position of the second 242 tone resource unit (80 MHz) and the allocation position of the second 242 tone resource unit (40 MHz) allocated on the 40 MHz bandwidth may be set to be the same. Shifting to the starting point of the left guard tone may be performed to set the allocation position on the 40 MHz bandwidth as described above.

To adjust the above position setting, the sum of the first leftover tone, the DC tone, and the second leftover tone can be set to 12 tones, and the remaining tones (512 tons-(484 tons + 12 tons) = 16 tones). May be set to the left guard tone and the right guard tone.

In FIGS. 9 to 11, allocation of the first 242 resource unit 40 MHz and the second 242 resource unit 40 MHz corresponding to the third 242 resource unit 80 MHz and the fourth 242 resource unit 80 MHz is not disclosed. It may be allocated in the same manner as the allocation method for the first 242 resource unit (40 MHz) and the second 242 resource unit (40 MHz) allocated corresponding to the first 242 resource unit (80 MHz) and the second 242 resource unit (80 MHz). have.

In FIG. 12, a method in which a 242 ton resource unit is divided into smaller resource units (56 ton resource unit, 26 ton resource unit) is disclosed.

Referring to FIG. 12, according to the present embodiment, the 242 ton resource unit may be divided into a combination of resource units of a relatively smaller size. For example, the 242 ton resource unit may be configured based on at least one 56 ton resource unit and / or at least one 26 ton resource unit.

Referring to the left side of FIG. 12, four 56 ton resource units (56 ton * 4 = 224 tons) may be used instead of the 242 ton resource unit. In this case, a sufficient number of leftover tones may be included within 242 tons. Thus, the leftover tone can be used as the guard tone.

Referring to the middle of FIG. 12, nine 26 ton (26 ton * 9 = 234 ton) resource units may be used instead of the 242 ton resource unit. In this case, 8 tons of leftover tones may be included in the 242 ton resource units, and 8 tons of leftover tones may be used as guard tones for 9 26 ton resource units.

Referring to the right side of FIG. 12, two 56 ton resource units and five 26 ton resource units may be used instead of the 242 ton resource unit. In this case, a sufficient number of leftover tones can be guaranteed without using some resource units (for example, 26 ton resource units or 13 ton resource units divided into 26 tons).

Alternatively, change the configuration of 56 ton resource unit and 26 ton resource unit to configure 56 ton resource unit into two 26 ton resource unit and leftover tone, or combine two 26 ton resource unit and leftover tone to add 56 Tone resource units may also be configured.

In this case, four 56 ton resource units and one 26 ton resource unit are used instead of two 56 ton resource units and five 26 ton resource units, or three 56 ton resource units and three 26 ton resource units. Resource units may be used.

In FIG. 13, when the shifting of the bandwidth is impossible, a method of allocating resources on a 20 MHz bandwidth is disclosed. According to an embodiment of the present invention, when performing resource allocation for a 20 MHz bandwidth (or when performing resource allocation for an STA supporting a 20 MHz front end), shifting of bandwidth may be impossible. This is because when the shifting for the bandwidth is performed, the bandwidth may be operated with low efficiency because the resource block is mode shifted.

Therefore, when shifting with respect to bandwidth is impossible, the following resource allocation may be performed.

In the 80 MHz bandwidth, the left guard tone (or left-most guard tone) and the right guard tone (or right-most guard tone) may be set to 11 to 10 tones, respectively. . In addition, the left guard tone, the first 242 ton resource unit (80 MHz), the first left over tone, the second 242 tone resource unit (80 MHz), the second left over tone, the DC tone, the third left over tone in the 80 MHz bandwidth, A third 242 tone resource unit (80 MHz), a fourth leftover tone, a fourth 242 tone resource unit (80 MHz), and a right guard tone may be allocated.

A left guard tone (6 tones), a 242 ton resource unit (20 MHz) + DC tone, and a right guard tone (5 tones) on a 20 MHz bandwidth may be allocated.

In this case, the 242 ton resource unit (20 MHz) allocated to the 20 MHz bandwidth may be allocated to correspond to the second 242 ton resource unit (80 MHz) or the third 242 ton resource unit (80 MHz) adjacent to the DC tone. In other words, the first 242 ton resource unit (80 MHz) and the fourth 242 ton resource unit (80 MHz) and the 242 ton resource unit (20 MHz) adjacent to an edge of the 80 MHz bandwidth may not correspond.

At this time, the positions of the second 242 ton resource unit (80 MHz) and the third 242 ton resource unit (80 MHz) may be adjusted based on the assignment of the leftover tone and set to correspond to the 242 ton resource unit (20 MHz).

In FIG. 14, when the shifting of the bandwidth is impossible, a method of allocating resources on a 20 MHz bandwidth is disclosed. In FIG. 16, a resource allocation method is disclosed on a 20 MHz bandwidth without shifting to the 20 MHz bandwidth based on an adjustment of the number of left guard tones / right guard tones defined in the 80 MHz bandwidth.

In the 80 MHz bandwidth, six left guard tones and five right guard tones can be set. Also, in the 80 MHz bandwidth, the left guard tone, the first 242 ton resource unit (80 MHz), the second 242 ton resource unit (80 MHz), the DC tone, the third 242 ton resource unit (80 MHz), and the fourth 242 ton resource unit (80 MHz) and the right guard tone can be allocated.

In this case, the 242 ton resource unit (20 MHz) is the first 242 ton resource unit (80 MHz), the second 242 ton resource unit (80 MHz), the third 242 ton resource unit (80 MHz) or the fourth 242 ton resource unit (80 MHz) ) May correspond to. That is, the 242 ton resource unit (20 MHz) may correspond to any 242 ton resource unit (80 MHz) of the four 242 ton resource units (80 MHz) included in the 80 MHz bandwidth.

This embodiment can be applied to the non-contiguous OFDMA allocation shown in FIG. 15. In detail, as illustrated in FIG. 15, the subband 1530 used by the STA 2 and the STA 3 in the target BSS may be discontinuous with the subband 1510 used by the STA 1. In this case, when a null subband is configured between the subband 1510 for STA 1 and the subband 1530 for STA 2 / STA 3, the corresponding null subband is an IFFT of a transmitter. The STA / ID2 may interfere with each other by the / IDFT operation.

For example, if each subband is independently filtered using two RF units, this interference problem can be solved. However, this embodiment proposes a technique for minimizing the influence of interference even when processing one OFDMA packet through an FFT / DFT module included in one RF unit.

Specifically, as shown in FIG. 15, when there is an OSBB that overlaps frequency with the target BSS, and there is a hearingable interfering source that can be received from the corresponding OBSS for a specific subband 1540, the target BSS In the above, interference of the subband 1510 for STA 1 and the subband 1530 for STA 2 / STA 3 may be reduced by controlling a resource unit in a frequency domain adjacent to the discontinuous band 1520. .

Specifically, the frequency chunk corresponding to a specific frequency band (for example, 20 MHz) is divided into a plurality of units (for example, resource units corresponding to 26 tones), and the leftover tone (left) generated in this division process is left. A first technique for allocating a -over tone to a frequency domain adjacent to the discontinuous band 1520 may be proposed. In addition, a frequency chunk corresponding to a specific frequency band (for example, 20 MHz) is divided into a plurality of units (for example, resource units corresponding to 26 tones), and the leftover tones generated in the classification process are respectively identified. A unit of a unit (i.e., a resource unit corresponding to 26 tones), and one unit closest to the discontinuous band 1520 among the plurality of units is a null unit (i.e., a unit / resource unit composed of null tones only). A second technique may be proposed.

In the first technique, a frequency chunk consisting of a relatively large number of tones (e.g., a chunk corresponding to 242 tones) is divided into a plurality of units of relatively small size (e.g., resources corresponding to 26 tones each). The leftover tone generated in the process of dividing the number of units) is used as a guardband for preventing interference, and all of the plurality of units can be used for data transmission, which has an advantageous effect in terms of data rate.

In comparison, in the second technique, a frequency chunk consisting of a relatively large number of tones (e.g., a chunk corresponding to 242 tones) is assigned to a plurality of units of relatively small size (e.g., 26 tones each). And at least one unit is used as a guardband for interference prevention, the data rate may be relatively lower than that of the first scheme, but has a more advantageous effect in terms of interference prevention effect. .

Hereinafter, the above-described first and second techniques will be described in more detail.

16 is a diagram for explaining an example of frequency resource allocation proposed in this embodiment. An example of FIG. 16 relates to the first technique described above.

In the example of FIG. 16, each of the frequency chunks corresponds to 242 tones and also corresponds to a 20 MHz band. That is, as shown in the middle of FIG. 12, an example of a case in which a frequency chunk corresponding to 242 tones is composed of only 26 tons of units (which can be represented by various names such as resource units and frequency units) is described. It can be applied to FIG.

As shown in Fig. 16, a chunk of 242 tones (i.e., frequency blocks / resources / intervals consisting of consecutive 242 tones) has eight leftover tones except 234 data tones (26 * 9 = 234). Is inserted into a gap between chunks of 242 tons. In other words, the second frequency chunk of FIG. 16 may be divided into a frequency region 1640 allocated to 234 data tones and a frequency region 1630 corresponding to eight leftover tones. That is, the resource allocation scheme described in FIGS. 3 to 14 may be further modified by the scheme of FIG. 16. For example, as used in the example of Figs. 3 to 14, the resource unit of 242 tons (i.e. chunk or 242 ton block) becomes 234 tons, and other resource units corresponding to 8 to 4 tons other than that are left as is. May be used as a leftover. In FIG. 16, an arrow inserted between chunks indicates a null tone. The number of null tones in the figure may be determined according to the specific number proposed in this embodiment. In the 80MHz bandwidth, it can be structured to put another unit corresponding to 26 tones near the DC tone. In this case, the 26 tone unit inserted into the center can be used for data or control signal. To be used, a specific number of null tones can be inserted into the structure ... (null tones) / 13 / DC / 13 / (null tones). In this case, the number of null tones may be eight or four.

As another example of the first technique, each thirteen tones near a DC tone can be utilized as a gap between tone blocks consisting of 234 tones to utilize more chunks (corresponding to 242 tones) simultaneously. have. That is, the left guard tone (shown in the frequency domain 1610 in FIG. 16) / 234/8/13/234/8 / DC / 8/234/13/8/234 / right guard tone or left guard tone / 234 / 13/8/234/8 / DC / 8/234/8/13/234 / The right guard tone allows the tone plan to be configured. If the sizes of the left and right guard tones are 12 and 11, respectively, it is applicable to the total 1024 point FFT when DC is 7 tons. In this case, even if a certain chunk (for example, the first frequency chunk of FIG. 16) is allocated a small BW user or a legacy user to generate interference, other interference except for the corresponding chunk may occur. The advantage is that any chunk (eg, a second frequency chunk corresponding to 242 tones in Fig. 16) can be assigned. Meanwhile, although FIG. 16 illustrates a case where a narrowband user or a user who uses a 20 MHz data field by a 64-point FFT is allocated (that is, when the OBSS uses a PPDU according to a conventional IEEE standard), the OBSS Even when the data field according to the HE format is allocated to the corresponding frequency band 1620, a guard tone can be inserted. This is because synchronization between the OBSS and the target BSS may be inconsistent, so that an ACI (adjacent channel interference) phenomenon may occur due to side lobes of a signal from the OBSS.

As another example of the first technique, (for ease of implementation) if the tone design in each chunk is as equal as possible, the size of the left and right guard tones are 12, 11 and DC is 7 Assume when tone (234 + 8 = 242 chunk configuration), left guard tone (12) / 234/8/8/234/13 / DC / 13/234/8/8/234 / right guard tone (11) The structure of can be used. Alternatively, the left guard tone (12) / 234/11/12/234/6 / DC / 6/234/11/12/234/11 may be formed and used. The remaining chunks, except for the center, can be repeated in the structure 12/234/11.

17 is a diagram for explaining an example of frequency resource allocation proposed in this embodiment. The example of FIG. 17 relates to the second technique described above.

The second technique, like the first technique, has the beneficial effect of reducing interference in discontinuous OFDMA allocation. That is, as described with reference to FIG. 15, when a receiveable interfering source by the OBSS or the like exists in a

specific subband

1520 and 1540, discontinuous OFDMA allocation is performed by controlling a frequency domain adjacent to the corresponding subband. Reduces interference due to

In detail, as shown in FIG. 17, a narrow band user or a legacy user may be allocated to a frequency region corresponding to the first frequency chunk to generate interference. For example, a hearable interfering source by the OBSS or the like illustrated in FIG. 15 may correspond to the first frequency chunk of FIG. 17, and a band for at least one of STA1, STA2, and STA3 of FIG. 15. This may correspond to the second frequency chunk of FIG. 17. That is, the frequency region corresponding to the first frequency chunk of FIG. 17 belongs to the OBSS, and the region corresponding to the second frequency chunk belongs to the target BSS, so that discrete OFDMA allocation may be problematic.

According to the example of FIG. 17, a second frequency chunk corresponding to 242 tones may be allocated in units (or resource units / units) corresponding to 26 tones. In this case, a total of 234 tones are used in nine units, and the remaining eight tones can be utilized as leftover tones. The left over tone may be used as a control signal transmission, a training signal, or the like, and may also be used for securing a guard band. The positions of these eight leftover tones may be variously set, but may be included between nine units and used for the purpose of the leftover tones (control signal transmission, training signal, guard band securing). That is, as shown in FIG. 17, the tone plan may be implemented in such a manner that one leftover tone is inserted between one 26 ton unit and the other 26 ton unit.

On the other hand, one unit 1730 that is closest to the first frequency chunk among nine units corresponding to 26 tones is preferably allocated to a null unit (or null resource unit / null resource unit) including only null tones. That is, in FIG. 17, one unit 1730 is preferably not used for transmitting user data or control signals in order to reduce interference due to discontinuous OFDMA. In FIG. 17, the number of units allocated as null units has been described as one, but this may be added in consideration of a data rate and the like. In addition, the example of FIG. 17 illustrates a case in which only a first frequency chunk is allocated a small BW user or a legacy user by OBSS. If there is a third frequency chunk (not shown), and that chunk is also assigned a small BW user or legacy user by the OBSS, at least one unit (not shown) adjacent to the third frequency chunk. May additionally be assigned a null unit. Meanwhile, FIG. 17 illustrates a case where a narrowband user or a user using a 20 MHz data field by a 64-point FFT is allocated (i.e., using a PPDU according to a conventional IEEE standard in an OBSS). A null unit 1730 may be inserted even when the data field according to the HE format is allocated to the corresponding frequency band 1720. This is because synchronization between the OBSS and the target BSS may be inconsistent, so that an ACI (adjacent channel interference) phenomenon may occur due to side lobes of a signal from the OBSS.

16 and 17 are described based on chunks corresponding to 242 tones, the present embodiment is not limited to these specific values. 16 and 17 show an example of dividing chunks corresponding to 242 tones into unit units consisting of 26 tones, the unit need not necessarily be 26 units. However, in FIG. 16, the chunk is divided into units and the remaining tones are preferably disposed to be adjacent to the first frequency chunk. In FIG. 17, when the chunk is divided into units, the first frequency chunk is divided among the divided units. At least one unit closest to is preferably including only null tones, and a leftover tone is inserted between each divided unit.

16 and 17, it is preferable that a station (that is, an AP or a non-AP STA) to transmit data can recognize that a large user or an existing user is assigned to the first frequency chunk. In general, since the WLAN system is capable of over-hearing, the target BSS may receive a packet from the OBSS and SIG A and / or SIB- according to the standard of the SIG channel (for example, HE or VHT). B) can be decoded to determine that the first frequency chunk is being used by the user or existing user. For example, SIG-A (for example, HE SIG-A) used in OBSS includes an indicator indicating whether the corresponding 20Mhz band is used or allocation information for the corresponding 20MHz band, so that the target BSS side can Due to the 20Mhz, it may be determined whether to perform discontinuous OFDMA allocation.

Additionally or alternatively, the target BSS checks whether the first frequency chunk is used for transmission through an energy detection technique, and performs discontinuous OFDMA assignment on the target BSS side due to the corresponding 20 Mhz. You can also decide if you should.

In FIG. 18, a PPDU format transmitted based on OFDMA by an AP or a non-AP STA according to the present embodiment is disclosed.

Referring to FIG. 18, the PPDU header of the MU PPDU includes a legacy-short training field (L-STF), a legacy-long training field (L-LTF), a legacy-signal (L-SIG), and a high efficiency HE-SIG A. -signal A), HE-SIG B (high efficiency-signal-B), HE-STF (high efficiency-short training field), HE-LTF (high efficiency-long training field), data field (or MAC payload) It may include. From the PHY header to the L-SIG may be divided into a legacy part and a high efficiency (HE) part after the L-SIG.

The L-STF 1800 may include a short training orthogonal frequency division multiplexing symbol. The L-STF 1800 may be used for frame detection, automatic gain control (AGC), diversity detection, and coarse frequency / time synchronization.

The L-LTF 1810 may include a long training orthogonal frequency division multiplexing symbol. The L-LTF 1810 may be used for fine frequency / time synchronization and channel prediction.

L-SIG 1820 may be used to transmit control information. The L-SIG 1820 may include information about a data rate and a data length.

The HE-SIG A 1830 may include information for indicating an STA to receive the DL MU PPDU. For example, the HE-SIG A 1830 may include an identifier of a specific STA (or AP) to receive a PPDU, and information for indicating a group of the specific STA. For example, when the HE-SIG A 1830 is used for the DL MU PPDU, it may also include resource allocation information for reception of the DL MU PPDU of the non-AP STA.

In addition, the HE-SIG A 1830 may include color bits information, bandwidth information, tail bits, CRC bits, and MCS (for the HE-SIG B 1840) for BSS identification information. It may include modulation and coding scheme information, symbol number information for the HE-SIG B 1840, and cyclic prefix (CP) (or guard interval (GI)) length information.

The HE-SIG B 1840 may include information about a length MCS of a physical layer service data unit (PSDU), a tail bit, and the like. In addition, the HE-SIG B 1840 may include information on an STA to receive the PPDU, OFDMA-based resource allocation information (or MU-MIMO information). When the HE-SIG B 1840 includes OFDMA-based resource allocation information (or MU-MIMO related information), the HE-SIG A 1830 may not include resource allocation information.

The HE-SIG A 1850 or the HE-SIG B 1860 may include resource allocation information (or virtual resource allocation information) for at least one receiving STA.

The previous field of the HE-SIG B 1840 on the MU PPDU may be transmitted in duplicated form in each of different transmission resources. In the case of the HE-SIG B 1840, the HE-SIG B 1840 transmitted in some resource units / resource units is an independent field including individual information, and the HE-SIG transmitted in the remaining resource units / resource units. The B 1840 may be in a format duplicated of the HE-SIG B 1840 transmitted in another resource unit. Alternatively, the HE-SIG B 1840 may be transmitted in an encoded form on all transmission resources. The field after the HE-SIG B 1840 may include individual information for each receiving STA that receives the PPDU.

The HE-STF 1850 may be used to improve automatic gain control estimation in a multiple input multiple output (MIMO) environment or an OFDMA environment.

The HE-LTF 1860 may be used to estimate a channel in a MIMO environment or an OFDMA environment.

The size of the FFT / IFFT applied to the fields after the HE-STF 1850 and the HE-STF 1850 and the size of the FFT / IFFT applied to the field before the HE-STF 1850 may be different. For example, the size of the FFT / IFFT applied to the fields after the HE-STF 1850 and the HE-STF 1850 may be four times larger than the size of the IFFT applied to the field before the HE-STF 1850. . The STA may receive the HE-SIG A 1830 and may be instructed to receive the downlink PPDU based on the HE-SIG A 1830. In this case, the STA may perform decoding based on the FFT size changed from the field after the HE-STF 1850 and the HE-STF 1850. On the contrary, when the STA is not instructed to receive the downlink PPDU based on the HE-SIG A 1830, the STA may stop decoding and configure a network allocation vector (NAV). The cyclic prefix (CP) of the HE-STF 1850 may have a larger size than the CP of another field, and during this CP period, the STA may perform decoding on the downlink PPDU by changing the FFT size. For convenience of description, the portion to which the FFT / IFFT size of 4 times is applied may be referred to as the second portion of the PPDU, and the portion to which the original FFT / IFFT size is applied may be referred to as the first portion of the PPDU.

An access point (AP) may allocate each of a plurality of radio resources for each of a plurality of STAs over the entire bandwidth, and transmit a physical protocol data unit (PPDU) to each of the plurality of STAs through each of the plurality of radio resources. Information about allocation of each of a plurality of radio resources for each of the plurality of STAs may be included in the HE-SIG A 1850 or the HE-SIG B 1860 as described above.

In this case, each of the plurality of radio resources may be a combination of a plurality of radio resource units defined with different sizes on the frequency axis.

Each of the four

frequency bands

1882, 1882, 1883, and 1884 illustrated in FIG. 18 may correspond to the frequency chunks illustrated in FIGS. 16 and 17. That is, a small BW user or a legacy user may be allocated to the at least one band / region of the four frequency bands shown by the OBSS. For example, when a small BW user or a legacy user is allocated on the first frequency band 1882, the first technique described with reference to FIG. 16 for the second frequency band 1882. Alternatively, the second technique described with reference to FIG. 17 may be described.

For example, in the case of downlink communication, when the second frequency band 1882 adjacent to the first frequency band 1882 is allocated for a second STA belonging to the target BSS, the AP may be configured to have a first frequency band 1881. It may be determined whether it is allocated to the first STA (narrowband user or existing user) belonging to the OBBS.

If the first frequency band 1882 is assigned to a narrow band user or a first STA belonging to an existing user, the AP of the target BSS corresponds to a plurality of units (eg, 26 tones) belonging to the second frequency band 1882. At least one resource unit closest to the first frequency band 188 among nine resource units may be allocated as a null resource unit and used for the second STA.

In this case, one leftover tone may be included between nine resource units included in the second frequency band 1882. Each of the four

frequency bands

1882, 1882, 1883, and 1884 illustrated in FIG. 18 may correspond to a 20 MHz band, and only some of them may be included. For example, when the first and third frequency bands are allocated narrowband users or first and third STAs belonging to an existing user, the AP of the target BSS may include a plurality of units belonging to the second frequency band 1882. For example, among the nine resource units corresponding to 26 tones, the resource unit closest to the first frequency band 1801 and the resource unit adjacent to the third frequency band 1883 are allocated as null resource units. Can be used for the second STA.

The operation on the downlink may also be applied to the operation on the uplink.

Referring to FIG. 19, a wireless device may be an AP 1900 or a non-AP station 1950 that may implement the above-described embodiment.

The AP 1900 includes a processor 1910, a memory 1920, and a radio frequency unit 1930.

The RF unit 1930 may be connected to the processor 1910 to transmit / receive a radio signal.

The processor 1910 may implement the functions, processes, and / or methods proposed herein. For example, the processor 1910 may be implemented to perform the operation of the AP according to the present embodiment described above. The processor may perform the operation of the AP disclosed in the embodiment of FIGS. 1 to 18.

The non-AP STA 1950 includes a processor 1960, a memory 1970, and a radio frequency unit 1980.

The RF unit 1980 may be connected to the processor 1260 to transmit / receive a radio signal.

The processor 1960 may implement the functions, processes, and / or methods proposed in this embodiment. For example, the processor 1960 may be implemented to perform the non-AP STA operation according to the present embodiment described above. The processor may perform the operation of the non-AP STA in the embodiment of FIGS. 1 to 18.

For example, the processor 1960 may receive downlink data or transmit uplink data based on a resource unit (or radio resource) scheduled by the AP.

Processors

1910 and 1960 may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, data processing devices and / or converters to convert baseband signals and wireless signals to and from each other. ) May include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium, and / or other storage device. The

RF unit

1930 and 1980 may include one or more antennas for transmitting and / or receiving a radio signal.

When the embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) for performing the above-described function. Modules may be stored in

memory

1920, 1970 and executed by

processors

1910, 1960. The

memories

1920 and 1970 may be internal or external to the

processors

1910 and 1960, and may be connected to the

processors

1910 and 1960 by various well-known means.

Claims

In a method for transmitting a signal including a data field in a wireless LAN,

An access point (AP) assigning a second frequency band adjacent to a first frequency band to a second station, the second frequency band including a plurality of resource units; And

Transmitting a signal comprising the data field to the second station over the assigned second frequency band,

When the first frequency band is allocated to a first station, the AP allocates the second station to a null resource unit, which is a resource unit adjacent to the first frequency band among the plurality of resource units. How to feature.
According to claim 1,

In the frequency domain, at least one left-over tone is included between the plurality of resource units.

Characterized in that the method.
According to claim 1,

And wherein the first frequency band is allocated by a neighboring AP.
The method of claim 1,

And wherein each of the first and second frequency bands corresponds to a 20 MHz band.
The method of claim 1,

When the AP allocates a third frequency band adjacent to the second frequency band to a third station,

A resource unit adjacent to the second frequency band among the plurality of resource units included in the third frequency band is used as a data signal for the third station,

When a neighboring AP allocates a third frequency band adjacent to the second frequency band to a third station,

A resource unit adjacent to the second frequency band among the plurality of resource units included in the third frequency band is allocated to a null resource unit.

Characterized in that the method.
The method of claim 1,

The data field is included in a PPDU including a first portion and a second portion, wherein the first couple of PPDUs is configured by a first point FFT operation, and the second portion of the PPDU is the second point IFFT. And wherein the frequency bandwidths of the first portion of the PPDU and the second portion of the second PPDU are set equally.
In an access point (AP) for transmitting a signal including a data field in a wireless LAN,

An RF unit for transmitting a radio signal; And

Connected to the RF unit,

Assigning a second frequency band adjacent to a first frequency band to a second station, wherein the second frequency band includes a plurality of resource units,

Transmit a signal comprising the data field to the second station over the assigned second frequency band,

When the first frequency band is allocated to the first station, the AP is configured to allocate the second station as a null resource unit to a resource unit adjacent to the first frequency band among the plurality of resource units. felled

Control unit

Containing

AP.
The method of claim 7, wherein

In the frequency domain, at least one left-over tone is included between the plurality of resource units.

AP characterized in that.
The method of claim 7, wherein

And wherein the first frequency band is allocated by a neighboring AP.
The method of claim 7, wherein

Each of the first frequency band and the second frequency band corresponds to a 20 MHz band.
The method of claim 7, wherein

When the AP allocates a third frequency band adjacent to the second frequency band to a third station,

The control unit,

A resource unit adjacent to the second frequency band among the plurality of resource units included in the third frequency band is used as a data signal for the third station,

When a neighboring AP allocates a third frequency band adjacent to the second frequency band to a third station,

A resource unit adjacent to the second frequency band among the plurality of resource units included in the third frequency band is allocated to a null resource unit.

AP characterized in that.
The method of claim 7, wherein

The data field is included in a PPDU including a first portion and a second portion, wherein the first couple of PPDUs is configured by a first point FFT operation, and the second portion of the PPDU is the second point IFFT. Wherein the frequency bandwidths of the first portion of the PPDU and the second portion of the second PPDU are set identically.
In a method for transmitting a signal including a data field in a wireless LAN,

The transmitting station assigning a second frequency band adjacent to the first frequency band as a transmission band to an access point, wherein the second frequency band includes a plurality of resource units; And

Transmitting a signal including the data field to the AP via the assigned second frequency band,

When the first frequency band is used by another transmitting station, the transmitting station uses a resource unit adjacent to the first frequency band among the plurality of resource units as a null resource unit. How to.